1. Field of the Invention
The present invention relates to an image reading apparatus.
2. Description of the Related Art
Among conventional image reading apparatuses is an auto-document-feeder type image reading apparatus (hereinafter, “ADF image-reading apparatus”) that can successively read images from sheet-type media (hereinafter, “sheets”) stacked thereon. That is, such an ADF image-reading apparatus can automatically and successively feed a large number of sheets having a predetermined size for reading images therefrom.
Japanese Patent Application Laid-open No. H9-284478 discloses a conventional ADF image-reading apparatus. The conventional ADF image-reading apparatus includes an automatic feeding unit arranged on one side of the conveying unit, and a manual feeding unit arranged on another side of the conveying unit. The conveying unit conveys sheets from the automatic feeding unit and the manual feeding unit to an image reading unit. The conventional ADF-image reading apparatus switches the direction in which a sheet is conveyed (conveying direction) between a normal conveying direction and a reverse conveying direction. The automatic feeding unit automatically separates one sheet at a time from the sheets stacked thereon and feed the separated sheet to the conveying unit. On the other hand, sheets not separable in the automatic feeding unit (e.g., thin paper sheets or overhead projector (OHP) films) can be manually fed one by one from the manual feeding unit. More particularly, in a normal conveying mode, a sheet automatically fed from the automatic feeding unit is discharged to the manual feeding unit. Thus, in this case, the manual feeding unit functions as a stacking unit. On the other hand, in a reverse conveying mode, a sheet manually fed from the manual feeding unit is discharged to the automatic feeding unit. Thus, in this case, the automatic feeding unit functions as a stacking unit.
To achieve a compact structure, the conventional ADF image-reading apparatus includes a bend section in a conveying path between the automatic feeding unit and the manual feeding unit. However, when, e.g., a comparatively thin and easily bendable sheet is fed from the manual feeding unit, it is likely that the sheet gets bent or damaged at the bend section thereby causing jams in the conveying path. Moreover, when, e.g., a comparatively thick sheet having higher tolerance is fed from either of the automatic feeding unit and the manual feeding unit, it is likely that the sheet gets damaged by being forced to bend at the bend section. As a result, it becomes difficult to feed different types of sheets for reading images therefrom.